Depth of field is the distance between the nearest and farthest objects in an image of a scene that appear sharp and clear. By contrast, objects outside of the depth of field appear blurry. In conventional photography, the depth of field is a function of, among other things, the focal length of the camera lens and the f-number of the lens. However, simulated depth of field effects can be synthesized in digitally rendered images using several existing solutions. One existing solution simulates depth of field by tracing and integrating random rays of light sampled on the lens. Such a solution is accurate but slow. Another existing solution uses an accumulation buffer to reorganize rays of light as multiple pinhole cameras on the lens. Each individual camera can then be rendered using rasterization. This technique requires repeated rendering of the scene, which limits its effective speed. Accordingly, there is a need for an improved depth of field synthesis technique.